The infestation of an invasive moth that threatens 250 plant species has worsened in Santa Cruz County. And the pest, the light brown apple moth, has been found for the first time outside the nine counties where it previously had been located, according to state and federal agriculture officials.

One moth was found June 27 on Mare Island, in Solano County, and the next day another was found in a trap in an orange tree in the Los Angeles County city of Sherman Oaks, the first time the pest has been spotted in those counties.

The light brown apple moth, which had never before been detected in North America, was discovered in February in a backyard in Berkeley. Traps are now in place in 51 of 58 California counties in an effort by the U.S. Department of Agriculture and the California Department of Food and Agriculture to find and eradicate the moth, a native of Australia.

Officials said finding moths in new locations is bad news.

"We know that there are multiple generations of this pest during a year, and so we have been diligently looking for it since we deployed traps in April, hoping we wouldn't find it," Solano Agriculture Commissioner Jearl Howard said. "But we were constantly concerned that we would."

Federal and state quarantine regulations are in effect when discoveries are made, including mandatory inspections of retail nurseries. Under the rules, fruits and vegetables that are hosts for the moth may not be removed from school and community gardens.

In its larval stage, the moth destroys, stunts or deforms seedlings, spoils the appearance of ornamental plants, and injures deciduous fruit-tree crops, citrus and grapes.

The worst infestation is in Soquel, in Santa Cruz County, where 4,505 moths have been found in traps, the U.S. Department of Agriculture said on Monday. That is 1,676 more than were identified on May 26.